This proposed study evaluates the effectiveness of the primary pharmacological (Amitriptyline HCL) and self-regulatory (Stress- Management) therapies for chronic tension-type headaches, both separately and when combined. It also attempts to elucidate the psychological and biological mechanisms whereby pharmacologic and self-regulatory treatments produce improvement. Specifically, the primary aims are to: (1) Evaluate the separate and combined effects of amitriptyline therapy and limited- contact stress-management therapy with reference to placebo in a prospective outcome study conducted at two actual clinic sites using experienced neurologists and psychologists as therapists; (2) Evaluate treatment outcome on multiple indices, including recurrent headache activity (assessed from multiple perspectives), analgesic consumption, quality of life, health care costs, psychological distress and beliefs about headaches. Side-effects and acceptability of each intervention also will be assessed and preliminary information about characteristics of patients who are most likely to benefit from these therapies will be obtained; (3) Evaluate both immediate treatment effects (3 month) and intermediate (6 months) and longer term (l year) maintenance of improvements and examine the ability of psychophysiological and expectancy variables to predict the maintenance of improvements; (4) Elucidate therapeutic mechanism underlying the effectiveness of both amitriptyline and stress-management therapies by examining hypothesized electrophysiological, muscular and psychological mediators of improvement. Two hundred patients meeting International Headache Society diagnostic criteria for chronic tension-type headaches will participate in the following five phases of the study: (I) pretreatment evaluation that includes a structured diagnostic and psychosocial interview, neurological evaluation, psychosocial and psychophysiological testing, and one month of daily recording of headache activity and analgesic medication use; (2) treatment with placebo, amitriptyline HCL, stress-management therapy plus placebo, or stress-management therapy plus amitriptyline; (3) reassessment of (electrophysiological, muscular and psychological) variables hypothesized to mediate treatment outcome four and eight weeks after beginning treatment; (4) full reevaluation three months after beginning treatment (with neurological evaluation, psychosocial and psychophysiological assessment, and one month recording of daily headache activity and analgesic medication use); and (5) 6 and 12-month follow-up evaluations.